[Derwood1723]

Greetings,
I have an inverter drive that is not happy. I have an F-905 error that keeps coming up. It is a problem with a thermistor, and I have found the thermistor and found the correct resistance with a potentiometer to keep me running. Well it only worked for a little while, and i cannot find the correct resistance again. So I believe that there is more to this problem. I have checked just about everything else and it all comes down the the drive itself. This is getting way above my head, and I was wondering if anyone had some suggestions where to get this thing fixed. I found Alfa-inc. and they have been fairly reasonable, with good turn around time. Also, is there any kind of upgrade that is out there? Thank for the help in advance!

[WCIS]

The thermistor is used to sense the temperature of the heat sink. The firmware in the drive/inverter monitors this constantly and the checks for steady state readings. When it sees a steady state reading it figures the thermistor has failed.

If you're competent enough to wire in a pot to fool the drive you should be able to do the following:

1) Be sure the heat sink is as clean as you can get it using compressed air FROM A DISTANCE. Don't use 120 psi shop air from a home made nozzle an inch away from the circuit board. You can blast other stuff off the circuit board that you really need. Or create a short circuit without realizing it.

2) Be sure all the power semiconductors are firmly seated against the heat sink. If any are loose you need to verify there isn't any dust, grit, etc. between the semiconductor and the heat sink. If the heat sink compound (white stuff) has dried out you need to remove the old and replace it. If you remove any semiconductor from the heat sink you need to be sure you get it mounted flat against the heat sink during re-assembly and USE FRESH HEATSINK COMPOUND.

3) Check the cooling fan for proper speed. The bearings could be bad and the fan won't turn fast enough to keep the heat sink cooled. If it's questionable then replace it. www.jameco.com has a wide selection of fans. Don't worry so much about brand name, etc. Just match the voltage, physical size AND flow direction. They are cheap enough to have a spare and one day the mfg may decide to discontinue that version.

4) Replace the thermistor. You might have better luck finding a replacement at Newark | US - Electronic Components Distributor | Electronic Parts Distributor, or Mouser Electronics. Use the same guidelines as when replacing semiconductors. While the thermistor isn't generating heat it needs to sense it accurately. Keep it clean, and firmly seated against the heat sink.

Be careful, use your head, and DON'T FORCE ANYTHING to move. The semiconductor(s) may be adhered to the heatsink with nothing more than surface tension - which is GOOD and means there's nothing wrong there any nothing further needs to be done - but a mis-placed screw driver used as a pry bar can crack the semiconductor case and ruin it. Just be damn sure there isn't a screw holding it that you've missed.

WC

[Derwood1723]

That is all good information, thank you, but I still can't fool the drive anymore with the pot. So that is why I feel that my problem lies somewhere deeper than just in the thermistor.

[WCIS]

Well, I thought I was giving you what you needed to repair your problem - not help you continue to limp along. I've repaired quite a number of DC drives and AC inverters over the years. And, thermistor faults were always related to what I have already outlined.

Good Luck

[Derwood1723]

I want to find out what exaclty my problem is. I had put on the pot to determine if the thermistor was the problem or not. I found the resistance value of 28k ohms to show a displayed temp of 18 degrees C. I found this temp by pulling up V1-13 on the display of the inverter. The problem is that it worked for a little while. With the junk thermistor it would read a temp of -24.0 to -30.0 degrees. Why can i not bring up the display of V1-13, showing that thermistor, and I can attach my pot and vary the ohms from 1k to 400k and the temp not change? I think this is telling me that even if i change the thermistor I'm still going to have problems.

[mike_Kilroy]

sounds like your thermistor input circuit is bad. most thermistors, NTC & PTC, have switch point or knee around a couple k; most drives have set point around 3-10k -- anything above is good, below bad -- or vice versa. none will have switch point over 100k. thermostats of course are 0 ohms or open so setpoint still set around 1k to trip. if you can go 1-400k then input is prob bad - unless your thermistor is a special one that is semiconductor based and polarity sensative like a KTY unit - then your pot will not simulate it correctly.

[jimmy111]

I have a Yaskawa 626VM3C CIMR-VMC25P5 that shows code F-602 from time to time. The manual says this happens when voltage falls below 210vdc. Is the VDC a typo? Also the drive is supposed to be rated at 200-220vac so why would it fault out at 210 v to begin with. Is this control voltage?
Thanks

[macrocontrols]

can you please forward the user manual to my mail id : [email protected]

[Teetop]

I'm having they exact same issue on a Tree mill. I have a potentiometer from an AC motor. how would you wire that to the thermistor

[ggtech]

I'm having they exact same issue on a Tree mill. I have a potentiometer from an AC motor. how would you wire that to the thermistor

Mine is now fixed. Measure your thermistor before doing anything. Mine turned out to be working. It should show some resistance. Blast it with cold air from a computer cleaner can, it should change.

In my case it ended up being a bad trace on the board going from the the ribbon connector to a capacitor on the board. Had to take it to a repair shop and it took the technician some time to find the fault. He ran a wire between the 2 points.hope this info helps others.

[mactec54]

Mine is now fixed. Measure your thermistor before doing anything. Mine turned out to be working. It should show some resistance. Blast it with cold air from a computer cleaner can, it should change.

In my case it ended up being a bad trace on the board going from the the ribbon connector to a capacitor on the board. Had to take it to a repair shop and it took the technician some time to find the fault. He ran a wire between the 2 points.hope this info helps others.

So had the cap damaged the trace, this can be a common problem, capacitors should be changed every 5 years in these drives, if you have the manual, it will tell you to do this to prevent damage to the boards.

[EduardoAEBC]

Do you have photos of the bridge I made?

[mactec54]

I'm having they exact same issue on a Tree mill. I have a potentiometer from an AC motor. how would you wire that to the thermistor

You would not wire the pot to anything, to do with the thermistor

[Teetop]

You would not wire the pot to anything, to do with the thermistor

heatsink thermistor 25.53 ohms - temperature reading V1-13 -28.0 C
Motor thermistor 7.5 ohms - temperature reading V1-12 25.2 C
any way to trick the input with a Pot to get a reading 0f 7.5 ohms for the heatsink

[omf1]

Help
I have a Hurco BMC 30/d\D with a Varispeed 626VM3.
With a spindle not ready alarm
Varispeed has a F200 code
Is there any hope?

[WCIS]

Help
I have a Hurco BMC 30/d\D with a Varispeed 626VM3.
With a spindle not ready alarm
Varispeed has a F200 code
Is there any hope?

Here's a link to the operator's manual which was a very simple matter of doing a google search using your text above:

http://www.yaskawa.com/site/dmspindle.nsf/link2/TKUR-5EKT4M/$file/SIE-S626-6C.pdf

The F200 diagnostic code refers to the internal magnetic contactor. Read the manual on page 205. Although the manual lists possibilities within the inverter I would check for proper external signals first. After you've verified all proper signals to the inverter, then suspect the inverter itself. Begin with the E-stop circuitry. Sometimes the internal fault relay contacts are wired in series with the E-stop input which is totally redundant and un-necessary and will have you sniffing out the wrong path. If that is the case you need to find out what caused the fault relay to trip and correct it.

Going back to the e-stop (emergency stop) circuit. My prime suspect would be the e-stop panel switch. Most often a screw terminal loosens and a wire falls out. If wires are tight check the contact. With control power off use an ohmmeter to check continuity of the switch contact. Reading should be near zero ohms with e-stop switch out and infinity with the switch pushed in. I have made lots of money going to a trouble call only to find the e-stop was pushed in and no one knows "how it got that way."

Careful poking around with a suspected loose connection as you may knock that loose wire into something with a higher potential and fry something you may need.

[omf1]

Thak you. That would be great.
I will let you know

[gollame]

I Have a F602 / F604 alarm this was intermittent but now occurs at start up all the time!

I understand that this is an input power alarm or phase out etc I have increased the supply power from 195V to 210V all three phases are present
is this generally considered a repair scenario or is there anything I can do to fix.

I have some experience in repairing inverters etc but this is my first 626VM3 fault and I have nothing more than the manual from this forum.

Appreciate any guidance

[SAJA]

Hello Friend

any chance you remember how you remedied this problem, I have exactly the same situation on my inverter.

Thanks

[Christian_]

Hi guys, I have a 626vm3 with an f-600 fault can anyone help out?